Cod sursa(job #524392)

Utilizator zalmanDanci Emanuel Sebastian zalman Data 21 ianuarie 2011 08:41:54
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.85 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#define NMAX 100010
using namespace std;

int N, M, S, i, a, b, d[NMAX];
vector<int> v[NMAX];
queue<int> q;

void in(void)
{
	FILE *f = fopen("bfs.in", "r");
	fscanf(f, "%d%d%d", &N, &M, &S);
	for(i = 1; i <= M; ++i)
		fscanf(f, "%d%d", &a, &b),
		v[a].push_back(b);
	
	fclose(f);
}
void BFS(void)
{
	memset(d, -1, sizeof(d));
	q.push(S);
	d[S] = 0;
	
	while(!q.empty())
	{
		int nod = q.front();
		q.pop();
		
		for(i = 0; i < v[nod].size(); ++i)
		{
			int adiacNod = v[nod][i];
			if(d[adiacNod] == -1)
				q.push(adiacNod),
				d[adiacNod] = d[nod] + 1;
		}
		
	}
}
void out(void)
{
	FILE *g = fopen("bfs.out", "w");
	for(i = 1; i <= N; ++i)
		fprintf(g, "%d ", d[i]);
	
	fclose(g);
}
int main(void)
{
	in();
	BFS();
	out();
	
	return 0;
}